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NOV- 14, F HOLMES Re. ROTARY VALVE Original Filed June 7, 1928 4 Sheets-Sheet l 3 Lu W m 1 a $1;

freclsrjclfillflolnws Q$ fjwuem to a I a 1 I o Momma a F. J. HOLMES ROTARY VALVE Nov. 14, 1933.

4 Sheets-Sheet 2 Original Filed June '7. 1928 w f'nedfiricii JlYolnzes Nov. l4, 1933.

F. J. HOLMES ROTARY VALVE I Original Filed June 7, 1928 4 SheetsSheet 5 ml i'fledenidij K152707265 6mm m3 0 F. J. HOLMES ROTARY VALVE Nov. 14, 1933.

Original Filed June 7, 1928 4 Sheets-Sheet 4 1 r I adorn m 3 wi m mw Reissuecl Nov. 14, 1933 UNITED STATES ROTARY VALVE 7 Frederick J. Holmes, Detroit, Mich., assignor, by

mesne assignments, to Rotary Holding Com pany, Detroit, Mich., a corporation of Michi-- gan.

Original No. 1,754,019,

dated April 3, 1930, serial.

No. 283,619,. June 7,. 1928. Applicationfor re-* issue June 29, 1932.

22 Claims.

This invention relates to rotary valves for machines such as internal combustion engines, compressors or the like which include a working piston and cylinder to which fluid is admitted and exhausted through a port and has for its principal object to provide a new and improved construction for such valves that will be highly efficient and successful in practical, commercial operation and whereby the use of poppet valves for such machines, with all of the disadvantages inherent thereto, may be obviated and a valve structure employed that will increase the efiiciency and flexibility of performance of such machines towards which desired results so much costly engineering effort, design and experimentation is at present being directed.

Another object is'to provide sealing means intermediate the rotary valve and the cylinder port through which the gases are admitted and exhausted, which sealing means will effectively prevent leakage of gases past the working sur- A further object is to so construct said sealing means that a restricted circuitous path around its contacting or bearing surfaces is provided and also preferably to include in such passage a sump or chamber for containing a lubricant or other liquid which will furnish a liquid seal to prevent gas leakage.

Another object is to provide a rotary valve particularly designed for use with an internal combustion engine and which valve includes a chamber of relatively large volume for the incoming fuel gases or mixture immediately adjacent to the engine cylinder and to provide an inlet valve opening of much greater area than heretofore obtained so that a marked increase of volumetric eniciency is secured.

Still another object is to construct a rotary valve for an internal combustion engine whereby an engine designed primarily for operation with gasoline as fuel may be operated with equal or even greater effici ncy with less volatile and relatively cheaper fuels such as fuel oil of from 28 to 32 Baum. I

A further object is to provide a practical rotary valve that is particularly. adapted for use with an internal combustion engine and of the type wherein the incoming gases are admitted through a conduit or chamber incorporated in the valve adjacent to a, conduit or chamber through which the outgoing exhaust gases are passed and to so construct the valve and associated parts that it will operate successfully and Serial No. 621,127

practically at the high temperatures encountered.

in internal combustion engines. 1 Another object is to providea practical commercially operative valve construction especially adapted for internal combustion engines that will posses all of the advantages of overhead feeding of the fuel without the disadvantages inherent in the use of the poppet valves at present universally employed, among which disadvantages maybe noted the scoring of the valve seating surfaces due to Wire drawing of the gases caused by the necessity of passing the gases at high velocity through restricted orifices, the necessity of overcoming the inertia of a large number of reciprocating parts, the burning and carbonizing of the valve seating surfaces and the excessive wear on the parts, and to provide a construction in which the advantages of rotary motion over reciprocating motion are secured with the added advantages of the elimination of a large number of parts heretofore necessary with poppet valves, the obtainingof a valve opening of much larger cross sectional area than possible with poppet valves and the securing of a full valve opening in but a small fractional part of the angular motion of the en ines crank shaft that is required to secure full. opening of a poppet valve and to secure a better cooling of the valve and associated parts than is possible with poppet valves as well 7 as a better compensation for rapid and marked variation in temperature.

A further object is to provide a construction of a cylinder head and rotary valve casing including a'practical, operative rotary valve that may be made and sold as an attachment capableof being substituted for the valve head of a standard commercial internal combustion engine.

Another object is to improve upon rotary valves of the type to which the present invention relates by providing inlet and exhaust ports at the periphery of the valve of relatively large arcuate dimensions thereby'to secure free flow of the gases to and from the cylinder and a full valve opening of .much longer duration than secured with prior constructions.

With these and other objects in view, my. invention consists of the novel construction, combination and arrangement of the parts hereinafter fully described and claimed and illustrated in the accompanying drawings in which:

Fig. 1 is a longitudinal section through a portion of the head of the engine, portions of cylinders cooperating therewith being also shown in section and a valve in the head being shown partly in section and partly in elevation;

' Fig. 2 is a section on line 2-.-2,-of Fig. 1;

Fig. 3 is a section on line 3-3, Fig. 2;

Fig. 4'is a section on line 44, Fig. 2;

Fig. 5 is a section on line 5 5, Fig. 1'-;

Fig. 6 is aperspective view of one of the sealing sleeves of the valve;

Fig. '7 is a perspective view of'one of the port takeups or sealing blocks;

Fig. 8 is a perspective view of the support and guide for the block shown in Fig. '7;

Fig.9 is a view similar to Fig. 2 showing a slightly modified construction;

Fig. 10 is a perspective view of the modified form of sealing block or takeup shown in Fig. 9;

Fig. 11 is a perspective view of the port an guide therefor;

Fig. 12 is a side elevation of the takeup block and guide assembled. As shown in the drawings the reference character 1 indicates the cylinder block of an internal combustion engine which, as shown in Fig. 1, includes a plurality of workng cylindersv each having a piston mounted for reciprocation therein. Suitablyfsecured to the block 1 is a combined cylinder head and valve casing 2, which, as shown, in-

cludes a cylindrical valve chamber 3 preferably surrounded by a water jacket 4 to which access may be had through an opening 5 normally closed by a'removable closure plate 6. The head 2 is provided with a plurality of ports 7,' one, for

each cylinder of the cylinder block.. Each port '7 is locatedv above its'respectivecylinder and in communication therewith and also communicates with the cylindrical valve casing 3. Admission and exhaust of gas through said port '7 to and from its respective cylinder is under the control of the rotary valve presently to be more fully described, mountedwithin the valve chamber 3. In order to insure effective sealing of the rotary valve, adjacent to each port'l, and to prevent leakage of gas past the valve contact surfaces 1 from exhaust to inlet or vice versa, sealing means Such are provided at the mouth of each port. sealing means preferably consists of means rigidly secured to the valve casing and forming therewith an annular recess and a member having a bearing surface for. contact with the periphery of the rotary valve and; a sleeve portion which extends into said recess and in contacting sealing engagement with the side walls thereof. .In the particular constructional exampleillustrated the means which is fixed to the-valve head for defining the annular recess. referred to comprises" a lower member having a laterally extending flange 18 which is suitably secured to the head 2 atthe lower end of the port '7 and which has a sleeve portion 9 located in spaced relationship to the side walls of the port? and defining with said side walls an annular recess. Mounted for re-' ciprocation within such recess and in neat sliding engagement with the outer periphery of the sleeve 9 and the walls of the port '7 is a sleeve-like extensionlO of a sealing member, having at the upper end thereof an enlarged head lladapted to contact in sealing engagement with the periphery of the rotary valve 21. Theheadll is in overlapping arrangement with'the upper end of the sleeve, 9 and is provided with a bore 12 of the same size and dimension asthe bore of the sleeve 9. It will be noted that the bearing surface between the sealing members 9 and 10 form'in effect a circuitous restricted path through which any ,gas would be compelled to pass in order to leak past the contacting bearing surface of said sealing members. For the purpose of insuring more effective sealing ofsuch members a sealing ring 13 may be located between the upper end of thesealing member 10 and the side walls of the port 7 and a similar sealing ring 14 may be provided between the upper end of the sleeve portion 9 of the lower sealing member and the sleeve portion 10 of the upper sealing member.

It will be noted that the sleeve portion 10 of the 'upper sealing member does not contact with the flange 8 of the lower member, but that a space 15 is left between said flange and the lower end of the member 10, this space providing a sealing chamber or sump in which any suitable liquid, such as oil, may be received to form a liquid seal intermediate the ends of the circuitous pathway above described. As shown, oil from the lubricating system of the engine is preferably supplied to the sump or chamber 15 through a bore 16 to which is connected 2. feed pipe 17 which leads to the oil pump, not shown, of the engine. The enlarged head 11 of the upper sealing member is provided with a concave bearing surface 18, as shown most clearly in Fig. '7 of the drawings, for contacting sealing engagement with the periphery of the rotary valve 21. Recesses or grooves 19 are provided in the sealing member 10 at the side edgesof the concaved bearing surface 18 for a purpose presently to appear. In order to hold the concave bearing surface 18 in sealing engagement with the periphery of the valve 21, springs 20 are preferably located within the sump 15 and abut against the lower end of the member 10 and the flange of the member 8 and normally serve to urge the'member 10 upwardly. It will be noted that these springs are submerged within the oil contained in the sump 15 and will be kept cool through such sump. V

Mounted for rotation within the housing 3 in by the circulation of oil 'head 2 is a' cylindrical rotary valve 21 having a concentric tubular core 22 constituting the exthe valve within its respective one of these grooves 24, the said t'akeup member being of a length substantially equal to the width of the groove in which it. is-seated. Extending to the exhaust manifold 22 from each of the grooves 24 is an exhaust port 25 and formed in the valve at proper points are intake ports 26 adapted to register. withthe openings l2 at the proper times during the cycle of operation of the engine. As shown particularly in Fig. 2-the exhaust port 25 extends through slightly less than ninetydegrees. The intake portassociated with saidexhaust port 25 and indicated at 26 extends through substantially ninety degrees but the advancing wall of this port, indicated at 27, has a cut-off flange 28' extending therefrom for the purpose of maintaining the opening 12 completely closed until the exhaust port 25 has passed out of communication with'said opening. The remaining space within the valve outside of the exhaust manifold 22 and" between exhaust port 26 and the exhaust .port

25 provides an intake-manifold 29, into which fuel will be directed from the supply port of the engine.

The ports 25 and 26 are arranged preferably in pairs, one port 25 and one port 26 being provided for each of the ports 7 and the same being so located as to operate in properly timed relation. Arranged between these pairs of ports is a fuel supply port 30 shown particularly in Fig. 5. Located at the outer end of this port 30 is a combined sealing and pipe connecting means comprising an annular flange 31 carried by a guide sleeve 32 similar to the sleeve 9 and providing an oil pocket 33 around the sleeve and within the port 30. A takeup block 34 similar to the block 10 extends around the sleeve 32 and within port 30 and is provided with aseal ring 35. A seal ring 36 is also carried by the sleeve 32. The head portion 37 of the takeup block is similar to the head portion of the block 10 already explained and is adapted to be held against the periphery of the rotary valve 21 by springs 38 seated in the oil pocket. A fuel supply pipe 39 opens into the sleeve 32 and as the oil pocket 33 is in communication through a bore 40 with a pipe 41 of the pressure lubricating system, it will be apparent that the springs will be constantly submerged and thus protected from injury by heat. The head of the block 34 engages within an annular groove 42 formed in the outer periphery of the valve 21 between the grooves 24 and,as shown particularly in Fig.5, a port 43 is formed in the valve 21 and extends through approximately two hundred seventy degrees so as to insure a sufficient supply of fuel to the intakemanifold 29.

For the purpose of maintaining a sealed connection between the rotary valve and its casing irrespective of any contraction or expansion of the parts that might take-place, there is provided within each of the grooves 24 and 42 a sealing sleeve 44 shown in detail in Fig. 6. This sleeve is preferably formed of three arcuate resilient plates 45, 46 and 47. .Plate is provided at the sides of each end with recesses 48 in the outer surface thereof and extending from the ends of the plate between these recesses aretongues 49 the outer faces of which are cut away as shown at 50. Cooperating with each end of the plate 45 are the adjacent ends of the plates 46 and 4'7. Each of these plates has tongues 51 extending from the sides thereof at its end, the tongues being cut away at their inner sides as shown at 52 so as thus to form a sliding lapping contact with the plate 45 withinthe recesses 48. The ends of the plates 46 and 47 nearest plate 45 have their inner faces cut away between the tongues 51 as shown at 53 to receive the tongues 49 which thus have a sliding lapping contact. As the tongues 49 have their outer faces cut away, transverse shoulders 54 are produced between the base portions of the tongues 51. These shoulders 54 cooperate with the shoulders to form pockets 55in which springs 56 are seated. These springs are adapted normally to hold the plates 46 and 4'? pressed away from the plate 45 without, however,

breaking the lapping contact between the co-' 44 is proportioned to fit snugly against the periphery of the valve within that groove 24 in which the band or sleeve is mounted. For'the purpose of holding said band or sleeve spaced from the inner surface of the valve casing or housing 3 is a spring 58 in the form of a transversely corrugated strip seated within the groove and outside of the sealing band or sleeve,

the ends of this spring terminating at opposite sides of the adjacent takeup member 10 or 34. These springs tend constantly to contract the sealing band 44 about the sleeve so as to provide a tight connection which will compensate for wear and any irregularities of contour. As before explained one of the sealing bands or sleeves 44 is located within each of the grooves in the not leak. As oil under pressure is located back of the respective takeup blocks or sealing members, this oil will act to press against said members and force them firmly against the valve. The springs are merely employed for holding the members in active position. The oil acts to provide the necessary liquid seal to prevent gas leakage. The oil also serves to prevent the springs from being burned or otherwise injured from excessive heat in the engine. bands or sleeves provide tight connections between the valve and the ends of the takeup members 10 and 34 and also constitute contractible inner casings for the valve so as to prevent leakage of pressure along the valve in any direction. As the valve is rotated in properly timed relation to the reciprocation or cycle of operation of the pistons of the engine by any suitable means not shown the port 26 will be brought into communication with the openings 12 in the members 10, thereby to supply fuel to the cylinders during the intake stroke. Likewise, at the proper time during the cycle of operation, the exhaust port The sealing 25 will be brought into communication with the opening 12 in the adjacent takeup member 10. The gases will be exhausted into the manifold 22 and the heat therefrom will serve to heat and bring to a highly vaporized condition the gas in the intake manifold 29. This vaporized gas will prevent direct conduction of heat from the-manifold 22 to the periphery of the valve. The periphery of the valve will be kept cool by the gas between'the manifold 22 and said periphery with the result that expansion and contraction will be reduced to the minimum. However, any such j expansion or contraction which may occur will be compensated 'for by the relatively movable sealingmembers indicated at 44, 34, and 10.-

Aside from their function as a means for forming a tight seal about the rotary valve, the

bands or sleeves 44 also serve to prevent oilfrom leaking into the cylinder parts from about the valve.

While itis preferred to depend on oil under pressure as a means for holding the takeup mem- Q bers pressed against the periphery of the valve,

thereby to supplement the action of the springs,

it is to be understood that, if preferred, a structure such asillustrated in Fig. 9 may be utilized. In this structure the ring 14 is dispensed with. Instead the guide member. 61 which forms the oil pocket 62 within port 63 receives the take-up member 64 which has a seal ring 65 extending therearound in sliding contact with the wall of the port 53. During the operation of I the engine pressure from the cylinder will be exertedover the end of the guide member 61 and back against the oil in the pocket 62 thereby forcing said oil to press against member 64 which, consequently,"

will be held with proper pressure against the periphery of the cylindrical valve.

Under some conditions'it might be possible to dispense with the pressure lubricating system altogether and to rely solely on the action of springs 66 against the takeup member 67 as shown in Fig. 12. It will be necessary, however, to have these springs submerged in oil as otherwise they would be soon rendered ineificient.

As will be seen from the foregoing a valve constructed in accordance with the principles of the present invention comprises a plurality of sleeves ,which surround the rotary valve one adjacent to ""each cylinder port, and which are held with a resilient pressure against the periphery of the valve in such a way that each sleeve is autosaid takeup memberhaving an opening for com- 'munication with the ports inthe valve and with met ically responsive to the pressure or suction conditions existing at any particular instant at the port of the cylinder which it controls.

Variations in suchpressure and suction condi-. tions between adjacent cylinders at any instant,

do not afiectthe efficiency of functioning of the valve because of the fact that each sealing sleeve is separate from the sleeve for the adjacent cylinder. The construction of the valve whereby the inlet and exhaust ports have an arc-shaped opening ofapproximately extent, insures that full valve opening can be maintained both for "intakeand exhaust for a greater extent of crankshaft movement than possible with the use of poppet valves. The construction of the sealing means at thecylinder ports results in the provision of restricted circuitous path between the bearing surfaces of the members which form such sealing means and due to-thiscircuitous path v together with the liquid seal formed by the oil in the sump intermediate the ends of such path escape of fuelor gas from one cylinder to an ad- 'jacent one is efiectively prevented.

, While I have shown a satisfactory constructional example embodying the principles of my invention, it :will be undersood that the invention is not limited to the specific constructional details illustrated and described, but that many changes, variations'and modifications may be,re-

sorted to without departing from such principles.

I claim:

1. Inan internal combustion engine the combination with a cylinder block, a head, thereon having an interior valve casing, there being a port extending from the interior of the cylinder block into the valve casing, of a'rotary valve within the casing, a guide member with and spaced 'fromthe walls of the port, a takeup member slidable upon the guide member andwithin theport, there being a lubricant pocketaround the guide member and back of the takeup member. and resilient means normally submerged in lubricant within the pocket for holding the takeup member pressed againstthe periphery. of the valve,

the port in the head.

2. In an internal combustion engine thecombi'enation with a head having a valve casing therein,- and a port leading from said casing throughone wall of the head for communication with a cylinder, of a valve mounted for rotation in the casing having fuel and exhaust ports=for alternate communication with the port in the head, a guide member withinthe port in the head, a takeup block extending therearound and slidable within said port, -means. for exerting constant pressure against one endof the takeup block for holding the other end thereof constantly in seal,- ing and working contact with the periphery of the valve, and a contractible sealing memberinterposed between the valve and its casing and abutting at its ends against the takeup block.

' 3;The combination with the headof an internal combustion engine having a' valve casing therein and a port extending from said casing through one wall of the head for communication with a cylinder, of a rotary valve within the casing having separate fuel and exhaust ports for successive communication with the port in the head and casing, a guide member within and spaced from the walls of the port inthehead, a takeup block extending therearound and slidable thereon, yielding means for holding said,

block in sealing and, working contact with the periphery of the valve, said valve having anannular groove into which the takeup block projects, means for subjecting the takeup block to end pressure for. holding the same in sealing contact with the, grooved valve, a contractible and expansibie sealing band within the groove abutting atv its ends against and held against rotation by the takeup block, and resilient means for holding said band pressed against the valve.

4. The combination with the. head of an internal combustion engine having a cylindrical valve casing therein provided "with a port extending through the wall of the head for communicationwith a cylinder, ofa takeup block slidably mounted. in saidport, a rotary valve in the casing having separate fuel and exhaust ports for successive communication with the ports in the block, meansfor maintaining a pressure against the takeup block for holding it in sealing and working contact with'the periphery of the valve,

being a-port extending from said'casing throughone wall of the head for'communication with the interior of a cylinder,:-a valve mounted for rotation within the casing having non-communicating concentric intake and exhaust manifolds therein, there being a port within the valvecom municating with the respective manifolds and movable into successive communication with the port in the head, there being an annular groove in the outer surface of the valve from which the 1 ports extend, a resiliently held takeup block slidv able in the port. in the head and casing and hav-{ ing a sealing working fit against the periphery of the valve and within the groove, an extensible. sealing band including lapping sections extending around the valve within the groove and abutmeans between the valve casing and the band for holding said band contracted about the valve to maintain a sealing fit between said valve and the band. I

6. In an internal combustion engine a head having a valve casing therein, there being a port extending from said casing through one wall'of the head for communication with a cylinder and another port extending from said casing through one wall of the head for communication with a fuel supply, a rotary valve within the casing having annular grooves, takeup blocks within the ports, means for subjecting said blocks to pressure for maintaining a sealing working connection between the blocks and the grooved portions of the valve, there being concentric intake and exhaust manifolds within the valve, there being a port in the intake manifold portion of the'valve for communication with the intake port and separate ports in the intake and exhaust manifold portions of the valve for successive communication with the port leading to the cylinder, and extensible, contractible, sealing bands within the respective grooves providing sealing working connections between the valve and its casing, the ends of the bands abutting against and being held against rotation by the takeup blocks. i

'7. In an internal combustion engine the com bination with a head havinga valve casing therein and a port leading from said casing through one wall of the head for communication with a cylinder, of a valve mounted for rotation in the casing having fuel and exhaust ports for alternate communication with the port in the head, a guide member detachably secured to one face of the head whereby, when the head is removed from its cylinder, said end of the member and its fastening means are exposed, said guide memher being extended into the port in the head, a takeup block extending around the guide member and slidable within the port, and means for exerting constant pressure against one end of the takeup block for holding theother end thereof constantly in sealingand working contact with the periphery of thevalve, said takeup block being removable with the guide member from the port.

8. In an internal combustion engine the combination with a head having a valve casing therein and aport leading from said casing through one wall of the head for communicating with a cylinder, of a valve mounted for rotation in the casing having fuel and exhaust ports for alter-- nate communication with the port in the head, a guide member detachably secured to one face of the head whereby, when the head is removed from its cylinder, said end of the member and its fastening means are exposed, said guide member being extended into the port in the head, a take up block extending around the guide member and slidable within the port, and means for directing a lubricant under pressure against one end of the takeup block thereby to hold the other end thereof constantly in sealing and working contact with the periphery of the valve.

9. In an internal combustion engine the combination with a head having a valve casing therein, and a port leading from said casing through one wall of the head for communication with a cylinder, of a valve mounted for rotation in the casing having fuel and exhaust ports for alternate communication with the port in the head, a guide member within the port in the head, a takeup block extending therearound and slidable within said por-t,-means for exerting constant pressure againstone end of the takeup block for-holding the other end thereof con stantly in sealing and workingcontact with the periphery of the valve, and a contractiblesealing member interposed between the valve and its casing, said takeup block constituting means for holding the sealing member against rotation with the valve.

10. The combination with the headof an internal combustion engine having a valve casing therein and a port extending from said casing through one wall of the head for communication with a cylinder, of a rotary valve within the casing having separate fuel and exhaust ports for successive communication with the port in the headand casing, a guide member within and spaced from the walls of the port in the head, a takeup block extending therearound and slidable thereon, yielding means for holding said block in sealing and working contact with the periphery of the valve, means for subjecting the takeup block to end pressure for holding the same in sealing contact with the valve, a contractible and expansible sealing band held against rotation by the takeup block, and resilient means for holding said band pressed against the valve.

11. The combination with the head of an internal combustion engine having a cylindrical valve casing therein provided with a port extending through the wall of the head for communication with a cylinder, of a takeup block slidably mounted in said port, a rotary valve in the cas ing having separate fuel and exhaust ports for successive communication with the ports in the block, means for maintaining a pressure against the takeup block for holding it in sealing and working contact with the periphery of the valve, a, sealing band extending around the valve heldagainst rotation by the takeup block, resilient spreading elements interposed between the ends of the sections of the band, a resilient means engaging the band and bearing against the valve casing for. holding said band contracted upon the valve to maintain a sealed working fit between the band and the valve, and means'for directing lubricant into the space between said band and the valve casing.

12. In an internal combustion engine a head having a valve casing therein, there being a port extending from said casing through one wall of the head for communication with a cylinder, and another port extending from said casing through one wall of the head for communication with a fuel supply, a rotary valve within the casing, takeup blocks within the ports, means for subjecting said blocks to pressure for maintaining a sealing working connection between the blocks and the valve, there being concentric intake and exhaust manifolds within the valve, there being a port in the intake manifold portion of the valvefor communication with the intake port and separate ports in the intake and exhaust manifold portions of the valve for successive communication with the port leading tothe cylinder, and extensible,

contractible, sealing bands providing sealing working connections between the valve and its casing, the bands being held against rotation by the takeup blocks. 7

13. The combination with a working piston and a cylinder having a port through which gas under pressure passes, of a valve casing, a rotary valve mounted within said casing for controlling means for rotating said valve in synchronism with the cycle of operation of said piston and cylinder, and means for compensating for expansion and contraction of the valve comprising a split sleeve having its entire periphery expansi-e bleinterposed between said valve and said casing and the free ends of said sleeve engagingv and maintaining sealing contact with said valve and easing adjacent to said port.

14. The combination with a working cylinder and piston of a valve casing mounted adjacent to said cylinder, a port for establishing communication between said casing and cylinder, ,a rotary valve in said valve casing operating in synchronism with the cycle of operation of said cylinder and piston and controlling the ingress and egress of gasthrough said'port and resilient sealing means flexibly surrounding said valve and interposedfreelybetween it andsaid casing, to

engage said casing with a resilient sealing pressure immediately adjacent to said port.

15. The combination with a working cylinder andpiston of a valve casing mounted adjacent to said cylinder, a port for establishing communication betweensaidcasing andcylinder, a rotary valve in said. valve casing operating in synchronism with the cycle of operation of saidcylinder and piston and controlling the ingress and egress of .gas through said port, expansible and contractible sealing means fiexiblysurrounding said valve and interposed between it and said casing, and resilient means between said valve and casing exerting a substantially equally distributed pressure about the entire periphery of said sealing means to hold said sealing means in sealing contact with said valve.

16. The combination with a working piston and a cylinder having a port for the. ingress and egress I of gas, an 'expansible and contractible sleeve surrounding said valve adjacent to said.

port and resilient means in engagement with said sleeve and normally tending to contract the same and holding it with a substantially uniform resilient pressure throughout its entire length against the periphery of said valve.

17. The combination with a working piston and a cylinder having a port for the ingress and egress of gas, of a valve casing,a valve mounted for rotation within said casing, a sealing means located at the mouth of said port and comprising an inner member arranged in spaced relationship with said casing and defining therewith an annular recess, and a sealing member in contacting engagement with the periphery of said valve and having. an annular sleeve projecting into said. recess in. sliding sealing contact with the walls of said recess but spaced from the bot-, tom thereof, said recessforming an oil receiving chamber or sump which forms a liquid seal intermediate the ends of the sealing contact sur face of said sleeve, Y

18. The combination witha Working piston and a cylinder having a port for the ingress and egress 'of gas, of a valve casing, a valve mounted for rotation within said casing, a sealing means located at. the mouth of said port and comprising an inner member arranged in spaced relationship with said casing and defining therewith anannular recess, and a sealing member in contacting engagement with the periphery of said valve and havinglanannular sleeve projecting into said recess in sliding sealing contact with the walls of said recess but spaced from the.bot tom thereof, said recess forming an oil receiving chamber ,or sump which forms aliquid seal intermediate the ends of the sealing contact surface of said sleeve and packing rings surrounding said sleeve. I

19, The combination with a plurality of juxtaposed working pistons and cylinders, each of said 7 cylinders having a port for the ingress and egress of gas, the ports of said cylinders being in spaced relationship, of a rotary valve having inlet and exhaust conduits, sealing means for said ports comprising a plurality of sleeves equally expansible and contractible throughout their entire periphery one for each of said ports surrounding said valve and arranged in spacedrelationship thereon and in alignment with said ports, and resilient means for each of-said sleeves for normally holding thesame with a yielding substantially equal pressure against the entire periphery of said valve. I r

20. The combination with a working piston and a cylinder, said cylinder having a port for the ingress and egress. of gas, of a valve casing, a

rotary valve mountedwithin said casing, sealing means located inthe mouth of said'port and comprising means associated with said casing to form an annular recess, a sleeve projecting into' said recess and in sealing contacting engagement with the, side walls thereof, an expansible and contractible sleeve associated with said first mentioned sleeve and surrounding said rotary valve and resilient means for holding; said expansible and contractible sleeve with a yielding pressure against the periphery of said valve. j

21. The combination with acylinder and piston, of a combined cylinder head and valvecasing having a conduit communicating with said cylinder for the inlet and exhaust of gases to and from said cylinder, a rotaryvalve mounted. in

said casing, a sealing member having a port slidably mounted in said conduit and means for urg-' ing said-member with a resilientpressure against said valve, a resilient split sleeve surroundingsaid valve and having its ends abutting against said 1 member and cooperating withit to provide a fluid tight seal of said valve and casing adjacent .to said port.

22. The combination with a cylinder and pis-, ton, of a combined cylinder head and valve casing having a conduit communicating with said cylinder for the inlet and exhaust of gases to and from said cylinder, a rotary valve mounted in.

said casing, a sealing memberhaving a port slidably mounted in said conduit and means for urging said member with a resilient pressure against said valve, a resilient split sleeve surrounding said valve and having its ends abutting against a fluid tight seal .of said valve and casing adjacent to said port, and resilient means in engage- ISG said member and cooperating with it to provide 

